Khat chewing has a long history in the culture and society of the Horn of Africa and Yemen. Extracts of leaves from khat have similar actions to that of amphetamines and contain the major psychostimulant cathinone, but also the mainly peripherally acting stimulants cathine and norephedrine. Fresh khat is rich in the major stimulant cathinone. In dried khat, cathinone content is greatly reduced,...